I see the fastest RAM allowed for this CPU is 3200MHz. Does that mean I cannot OC RAM with base speed of 3200MHz to speeds above 3200MHz?
My CPU base frequency is not the 3.6GHz listed, but because of Boost, it is always at about 4.8 GHz. So does that mean the speed limit on RAM is also above the 3200MHz?
The Maximum Speed in the specs is the highest speed that Intel validates the processor at and warrants its operation. You can attempt to use XMP profiles to get to higher memory speeds, but it may or may not work. In my experience, it is the quality of the motherboard that makes the biggest difference in how far it can be taken.
Unless you have increased the base clock, the limit on RAM speed is not affected.
I am not OC'ing the CPU, it seems the boost technology is what is increasing the speed. I have the Z590 Pro Wifi from MSI board. So, still not sure if buying DRAM with base speed of 3200MHz and using an XMP on it to above 3200MGHz to replace my current DRAM at 2133MHz OC'ed to 3200MHz.
That is good; Intel Turbo Boost technology is only adjusting the clock multiplier, not the base clock frequency, so does not affect the memory buses.
Ok, everything said, there are two things that you need to understand,
- The use of XMP to increase the speed of the memory buses is a form of overclocking and, like all forms of overclocking, is not guaranteed to work and could possibly void your processor warranty. Any form of overclocking could be subjecting the processor die to higher temperatures and (worse) more-rapid changes in temperature and these can have a accumulative detrimental affect on processor lifetime. In my experience, overclocking the memory buses is the mildest form of overclocking, however, and rarely has any affect.
- Overclocking the memory buses makes the memory buses more-susceptible to electrical noise. All components produce some amount of noise. As you increase frequencies, higher levels of noise is produced. If the level of noise on the buses reaches a certain threshold, data will become indistinguishable from noise and data failures can occur. Further, as components age, they produce more noise. It is thus possible that you could initially see this memory overclocking work fine but, with the passage of time, noise levels will increase and it will begin to suffer these failures (then).
Hope this helps - and doesn't scare you too much - but it is the reality of the situation,
So if I want my RAM to run at 3200MHz, it is better to buy RAM at that speed, rather than OC'ing RAM with base speed of 2133MHz, which is what I have?
The only CPU OC variable I have changed is the Processor Core Ratio, set to 47x. Does that seem to be too much in terms of not over-stressing the CPU?
You cannot overclock 2133 DRAM to 3200. You must have SODIMMs that actually support 3200 in order to take advantage of higher memory bus speeds.
Not sure I fully follow.
The MOBO (MSI Z590 Pro) supports up to 5300MHz with OC. But without changing the base clock speed, u said RAM limits don't change, so it is not possible to get above 3200 MHz with this CPU, even if I installed, say, DDR4 3600 (PC4-28800), replacing my DDR4 (pc3200)? XMP's won't take it higher since the base clock is set?
Btw, CPU-Z results shown below for the memory and CPU. Note 2 of the 4 sticks of DRAM are a bit slower, which I know brings the other 2 down.
The problem here is that the word overclocking is overused and creating confusion.
Processor core and memory bus speeds are controlled using a multiplication of the base clock speed. Increasing the multiplier from its default is not overclocking, per se. Overclocking is the act of increasing the base clock's speed itself. You typically use the XMP profiles to overclock (different meaning) the memory busses through increases in the memory bus multiplier.
If you have a i7-11700k, you have the capability to use any RAM that has a clock speed of 2133 to 3200. If you have 2133 RAM, there will be no XMP profiles in these DIMMs that allow the memory bus multiplier to be raised and take this RAM to higher speeds. If your system supports it, you can attempt to manually change this multiplier, without using an XMP profile, but there is no guarantee - and indeed a significantly lower possibility - of it working. If, on the other hand, you purchase DIMMs that are designed to support 3600, there will be XMP profile(s) that allow you to get beyond the processor's 3200 default and attempt to use the 3600 speed.
Clear as mud?